NEW YORK — A New York-bound Delta Air Lines flight from Israel declared an emergency and returned to Tel Aviv early Sunday after developing a mechanical problem, vexing passengers already on edge as Palestinian militants launched rocket attacks on the city.

Flight 469 — a Boeing 747 with 370 passengers and 17 crew members aboard — landed safely back at Ben Gurion Airport around 2:30 a.m. local time after flaps on the jumbo jet failed to retract properly on takeoff about two hours earlier, the airline said.

Delta spokeswoman Jennifer Martin said the crew made the emergency landing "out of an abundance of caution." She said there was no indication the plane's problem was related to the Israeli-Palestine conflict or terrorism.

Passenger Michael Simon said the crew disclosed an unspecified problem with the plane about a half-hour into the flight. The mood on board, he said, "was not so much panic as bewilderment and frustration."

"Obviously it has been a tense week in Tel Aviv," he said.

Simon said they soon started circling and dumping fuel.

Radar images showed Flight 469 in a holding pattern above the Mediterranean Sea, off the Israeli coast, for more than an hour.

Fire trucks and ambulances lined the runway and passengers were led off across the tarmac.

Simon said some were told they would be waiting more than 20 hours before being booked on a new flight to New York.

Flight 469 took off about 12:30 a.m. local time (5:30 p.m. Eastern time Saturday) and was due at New York's John F. Kennedy International Airport around 4:30 a.m. Eastern on Sunday.

The emergency landing only exacerbated heightened sensitivity in Israel amid the conflict.

Simon said passengers started arriving at Ben Gurion for the flight around 9:30 p.m. local time, just as sirens sounded to warn that Palestinian militants were sending a new round of rocket attacks toward Tel Aviv.

"People went from air raid to airport," Simon said. "What a jarring juxtaposition, even though pilots were clear this had nothing to do with Hamas."

The militant group said this week it intended to fire rockets at the airport and warned foreign airlines to stop flying to Israel. The Israeli military intercepted rockets headed toward the airport Friday and there was no disturbance to air traffic.

Delta issued a travel advisory earlier this week labeled "Israel Unrest" saying it would continue operating flights on the New York-Tel Aviv route but that it would allow passengers booked while the conflict continues to cancel or change their tickets without penalty.

The emergency landing of Flight 469 caused some residual delays in and out of Ben Gurion, but Simon said once the plane landed the airport appeared to be operating as usual — even with the threat of rocket fire.

"Unaffected," Simon said. "I looked at the flight board and not a single flight was canceled except for ours."